Int. J. Econ. Environ. Geol. Vol.Khan 8 (2 )et 9 -al.20 ,/ Int.J.Econ.Envi2017 ron.Geol.Vol. 8(2) 9-20, 2017 Open Access Journal home page: www.econ-environ-geol.org ISSN: 2223-957X Petrographic and Geochemical Analyses of Kirana Hills Shield Rocks around Sargodha and Economic Potential Muhammad Waseem Khan*, Syed Abbas Sultan, Iftikhar Alam, Muhammad Saqib Izhar Atomic Energy Minerals Centre, Lahore-54600, Pakistan *Email: [email protected] Received: 1August, 2016 Accepted: 15 February, 2017 Abstract: The present study deals with geochemical and petrographic analysis of the Kirana Hill shield rocks of Punjab plains from Buland, Hachi, Shaheen Abad, Shaikh and Machh hills. On basis of the current studies certain modifications have been made in the classification and nomenclature of rocks exposed in the study areas. Chemical analyses have also been carried out in order to calculate Cross Iddings, Pirsson, and Washington (CIPW) norms”, to strengthen nomenclature scheme and finally rocks are classified by using “MAGMA SOFTWARE”. Rhyolites predominate over the basalts/dolerites, andesites, and phyllite/ slate. Rhyolitic rocks are light grey, greenish grey and light brown in color, aphanitic in nature. The observed microscopic textures are aphyric, phyric or porphyritic and micropoikilitc. Moreover, some rhyolitic rocks also show flow texture. They are either cryptocrystalline to microcrystalline or microcrystalline to cryptocrystalline. No glassy material has been observed in any thin section. Mafic rocks are characterized by the presence of ferromagnesian minerals with plagioclase. Andesites exhibit mainly porphyritic texture, but aphyric texture has also been observed in few samples. Hydrothermal alterations are also very common in these rocks. Other rock assemblages identified during laboratory studies from Kirana area include: tuffs i.e. (Lithic Crystal Tuff and Lithic Tuff), basaltic andesite, rhyodacite/ dacite, slate/ phyllite, ankeritic rocks/ veins and quartzofeldspathic veins. Our studies also reveal that no evidence of quartzite has been found in the samples collected from above mentioned areas of Kirana, although it has been reported in previous literature. Iron (Fe) has been observed in rhyolite as well as other volcanic rocks of Kirana hills, its presence suggests magma from deep mantle instead of crustal melting / anatexis. In the present analysis some primary and secondary copper minerals including chalcopyrite, atacamite and malachite have been identified. Some anomalous values of the Rare Earth Elements are also observed. Inclusive geological investigations are recommended for better studies to appraise the potential of Iron (Fe), Copper (Cu) and trace/Rare Earth Elements (REE) in the area. Keywords: Mineral, petrographic, chemical analyses, rhyolite, hydrothermal alterations, Kirana Hills. Introduction samples have been analyzed in the mineralogy laboratory of AEMC, Lahore. The outcrops of this complex occur as isolated hillocks around Sargodha covering topographic Geological Setting sheets No. 44A/9, and 41A/3 and lie between longitudes 72˚38'39" to 72˚38'00" and latitudes The present Punjab Foreland basin was developed as 31˚51'00" to 32˚15'00" (Fig. 2). According to extensional basin within Late Proterozoic period of Ahmed (2000, 2004) the Kirana volcanics are a part Northeast Gondwana part of the Greater India, named of Neo-proterozoic Kirana complex. The Kirana as Kirana-Malani Basin (Chaudhry et al., 1999). In Hills form the western extension of the Precambrian this region the rhyolitic mass predominates over shield of India. It represents good example of dolerite/ basalt, andesite and dacite outcrops (Ahmad bimodal continental magmatism. Although the and Chaudhry, 2009). Major outcrops of the Kirana presence of intermediate rocks have been confirmed Hills are located near the city of Sargodha, Chiniot, by mineralogy division of Atomic Energy Minerals Shah Kot and Sangla Hills (Shah, 2009). These areas Centre Lahore. are solely occupied by the exposures of Proterozoic rocks without the occurrences of Phanerozoic However, these rocks are insignificantly small in lithologies. comparison to the acidic and mafic rocks. Present investigation focuses on the chemical and However, it is supposed that this complex supports petrographic analyses of shield rocks exposed in the as basement horizon for the Paleozoic to Eo- form of Kirana Hills to classify the rocks on the Cambrian sedimentary cover sequence exposed 100 bases of laboratory results of this research work. km north in the Salt Range (Fig. 1). The Kirana Hill This study encompasses the collection of more than rocks are very significantly economic sources of three hundred rock samples from surface and aggregates for the construction of road projects and subsurface of the Kirana Hills. Subsequently these 9 Copyright © SEGMITE Khan et al. /Int.J.Econ.Environ.Geol.Vol. 8(2) 9-20, 2017 civil super structures in the Punjab province of Calcium (Ca) and Magnesium (Mg) were estimated in Pakistan (Khan and Chaudhry, 1991; Khan, 2004). the fused sample either by volumetric analysis using EDTA as standard solution with different Ph and indicators or by atomic absorption spectrophotometer with the help of Z8000 Hitachi coupled with graphite furnace Japan, depending on the concentration and interfering environment of the matrix. Alumina (Al2O3) was estimated in the sample prepared by fusion with Aizarin red-S as chromogenic reagent by spectrophotometer. Titanium (TiO2) and phosphorous penta oxide (P2O5) were also estimated from multiacid leach solution by using hydrogen per oxide and ammonium vanado molybedate as chromogenic reagents for the complexion of both constituents respectively in their analysis spectrophotometrically with the help of Helios Epsilon Thermospectronic, single beam USA. Ferrous (Fe+2) was leached with nitric acid and hydrofluoric acid without any heating by keeping the sample over night and estimated volumetrically by using potassium di chromate as standard solution using Fig. 1 Location map of North Pakistan, square showing the Barium Diphenyl amin Sulphonate (BADAS) as study area. indicator. Materials and Methods Total iron (Fe) and manganese (Mn) were estimated through atomic absorption spectrometer (Z8000 Petrographic Analyses Hitachi coupled with graphite furnace, Japan) in multiacid leach solution. However, the iron contents Detailed petrographic studies of three hundred samples may also be determined volumetrically in the multiacid collected from the study area were carried out by using leach solution or fused sample using potassium standard petrographic Olympus BX 51 polarizing dichromate as standard solution and BADAS microscope fitted with Olympus DP12 camera. Several indication depending on the concentration of the iron. rock types have been described based on mineralogy and texture. The modal composition of hypabassal and Sodium (Na) and Potassium (K) were determined in microcrystalline volcanic rocks was volumetrically the multiacid leach solution of the sample on flame determined by recommended comparison charts, while photometer (Jenway PFP-7) with appropriate filter of composition of cryptocrystalline volcanic rocks was respective elements. It is an emission spectrophoto determined with the help of chemical analyses. meter technique. Important features of rocks are illustrated by photomicrographs. Carbon dioxide (CO2) was estimated indirectly in the form of carbonates volumetrically. Carbonates present Chemical Analyses in the samples were digested with excess hydrochloric acid of known strength. The excess acid was titrated Wet chemical analyses of more than two hundred with standard solution of sodium hydroxide using volcanic as well as hypabassal rocks samples were phenolphthalein as indicator. Volume of hydrochloric carried out to classify the rocks based on twelve major acid used for the digestion of carbonates was oxides and Loss on ignition (LOI) content as these determined from the volume of sodium hydroxide used rocks are fine grained, but results of some of the in titration. Data obtained was used to calculate the representative samples of each rock type are selected amount of carbon dioxide present in the sample. for this research work. Wet chemical analysis is a destructive technique and following constituents were Loss on Ignition was determined gravimetrically by estimated by using this technique. using Carbolite Furnace. The weighed sample was o Silica (SiO2) the main constituent of most of rocks was heated up to 900 C for one hour. The loss on weight estimated by gravimetrically. The samples were was calculated as percentage of LOI. digested with Nitric acid which removes all the soluble radicals except silica and separated through filtration. The oxides were converted to minerals, the calculated Finally the silica is estimated from residue with the abundance of the minerals is known as norm. The first treatment of Hydrofluoric acid gravimetrically. norm was devised by the four petrologists Cross, 10 Khan et al. /Int.J.Econ.Environ.Geol.Vol. 8(2) 9-20, 2017 Iddings, Pirsson, and Washington, and thus it is fruitful results. “MAGMA” software follows IUGS commonly referred to as CIPW norms (Philpotts, classification scheme to classify the rocks (Fig. 8). Fig. 2 Geological map of Kirana Hills. Colored rounded spots showing the locations of samples collected from the area, District Sargodha, Punjab (after Ahmed et al, 2007). Table 1. Chemical analysis showing high percentage of Iron (Fe) and low Nickel (Ni)